Appearance of Heterogeneous Macrophages During Development of Isoproterenol-Induced Rat Myocardial Fibrosis.

Macrophages appearing in lesions are polarized toward M1 (for inflammation) and M2 (for anti-inflammation/fibrosis) types. We analyzed immunophenotypes of macrophages appearing in myocardial lesion in rats injected once with isoproterenol (10 mg/kg body weight). Inflammation following myocardial necrosis on day 1 was seen with a peak on days 3 and 5, and thereafter, reparative fibrosis developed on days 7 to 28.